Study On The Effectiveness Of Microbial Fuel Cell As A Kitchen Wastewater Pre-treatment Process

With the serious global energy crisis and the enormous emissions of untreatedkitchen waste, this paper advocates a separate treatment of solid kitchen waste andliquid kitchen waste, in order to turn these considerable resources into clean biomassenergy. And study on the effectiveness of a single chambered microbial fuel cell(MFC) operated with liquid kitchen waste. Its bioelectricity generation potential andtreatment efficiency were evaluated under various organic loading rates anddifferent stack forms.Liquid kitchen waste can be used as a substrate in MFC with a great electricitygeneration. Different concentrations of liquid kitchen waste in MFC can produce anoutput voltage more than0.5V and achieve approximately90%organic removal rates.After a period of treatment, the effluent concentrations were less than500mg/L, closedto the organic loads of Urban sewage. The maximum voltage output together with agood treatment effect was observed at270020mg/L. The stable voltage, maximumpower density and the coulombic efficiency (CE) at that concentration was0.525V,5.6W/m3and9.45%, respectively. Correspondingly, the removal rates of TCOD,SCOD and TN were77%,90.3%and88.75%.The characteristic analysis of organics in liquid kitchen waste showed that thesingle-ring aromatic were the major components. After the treatment in MFC, thearomatic protein (tryptophan substances) and soluble microbial products inHydrophobic acid, Hydroponic neutral and Transphilic acid have been preferentiallyremoved. And the substances of humus in each component accumulated to someextent, which in turn made the operation in MFC more stable. Besides, in thehydrophobic components, the contents of TOC were less than30%, and theabsorption intensity of UV-254were less than20%.The research of various MFC stack forms suggested that reasonablecombinations of MFC with different internal resistances can weaken the differencesbetween cells and achieve voltage amplification without voltage reverse. What’smore, the COD mass balance in single MFC and packed MFCs were almost thesame. In other words, series-parallel stacks had little effect on the overall electricitygeneration and treatment efficiency of liquid kitchen waste in MFC.These results indicated that effective treatment and energy recovery of liquidkitchen waste can be obtained in MFC.